A gasification plant with a gasifier that gasifies carbon-containing material has conventionally been known. An example of such a gasification plant is an Integrated coal Gasification Combined Cycle system (hereinafter referred to as an “IGCC system”). In an IGCC system, a gasifier gasifies pulverized coal (carbon-containing material) and thereby generates a fuel for a gas turbine.
One of the known types of gasifier is a two-stage entrained flow gasifier composed of a combustor (combustion stage) and a redactor (gasification stage).
A combustor is a part that blows an oxidizing agent and carbon-containing material into an inside of the gasifier from a combustor burner for carbon-containing material, also blows an oxidizing agent and char separated and recollected from gas generated in the gasifier from a combustor burner for char, and combusts the carbon-containing material and the char (including partial combustion) to generate high-temperature gas.
A redactor is a part that blows carbon-containing material into the inside of the gasifier from a redactor burner and thermally decomposes and gasifies the carbon-containing material using the high-temperature gas generated in the combustor.
A technique related to such a two-stage entrained flow gasifier is one disclosed in Patent Literature 1. Hereinafter, description will now be made in relation to the technique disclosed in Patent Literature 1. In the following description, reference numbers used in Patent Literature 1 are represented in the brackets for the reference.
The technique disclosed in Patent Literature 1 (see claim 4, for example) changes a ratio (R/T) of distributing pulverized coal to the gasification stage with the property of the pulverized coal so that various threshold conditions required for stable operation of the gasifier can be satisfied. A “ratio (R/T) of distributing pulverized coal” is a ratio of a providing amount (R) of pulverized coal to the gasification stage to a total providing amount (T) of pulverized coal of a providing amount (C) of pulverized coal to the combustion stage and the providing amount (R) of pulverized coal to the gasification stage.